The technology of the present disclosure relates to an image forming apparatus.
Conventionally, there is known an image forming apparatus provided with an in-apparatus temperature sensor that detects an in-apparatus temperature and an outside-air-temperature calculation unit that calculates an outside-air temperature (outside-air temperature) on the basis of the in-apparatus temperature detected by the in-apparatus temperature sensor. It is proposed in this image forming apparatus that when a main power source is applied, an OFF time of the main power source is determined on the basis of an output signals from the in-apparatus temperature sensor and a fixing temperature sensor, and only when it is determined that the OFF time is longer than a predetermined time, a process for calculating the outside-air temperature is executed by the outside-air-temperature calculation unit.
In the image forming apparatus, there are only two states, that is, an OFF state of the main power source and an ON state thereof. In the meantime, however, in a recently developing image forming apparatus of energy saving type, in the ON state of the main power source, there are two modes, that is, a normal mode and a sleep mode in which the power is less consumed than in the normal mode.